NHR-23, a conserved member of the nuclear receptor family of transcription factors, is required for normal development in C. elegans where it plays a critical role in growth and molting. In a search for NHR-23 dependent genes, we performed whole genome comparative expression microarrays on both control and nhr-23 inhibited synchronized larvae. Genes that decreased in response to nhr-23 RNAi included several collagen genes. Unexpectedly, several hedgehog-related genes were also down-regulated after nhr-23 RNAi. A homozygous nhr-23 deletion allele was used to confirm the RNAi knockdown phenotypes and the changes in gene expression. Our results indicate that NHR-23 is a critical co-regulator of functionally linked genes involved in growth and molting and reveal evolutionary parallels among the ecdysozoa.

In this study, two methods for metallothioneins (MT) determination in a biological sample were compared. Particularly, twenty five human and nine pig blood serum samples and liver and kidney samples from thirty five carps (Cyprinus carpio) were analyzed by enzyme-linked immunosorbent assay and differential pulse voltammetry Brdickas reaction. The results obtained by these two methods were in good agreement. For commercially available MT standard the correlation coefficient between the single concentrations signal height was 0.99. In biological samples the correlation coefficients were 0.90 for fish liver and kidney samples, 0.91 for pig blood serum and 0.93 for human blood serum.